Artificial ear-drum



(No Model.)

A. V.'SANPORD.

ARTIFICIAL EAR DRUM.

No. 534,581. Patented Feb. 19, 1895..

VVitnesses: Inventor. x 7 WWW W Attorney.

UNITED STATES PATENT OFFICE.

ADDISON V. SANFORD, OF ELMIRA, NEW YORK.

ARTIFICIAL EAR-DRUM.

SPECIFICATION forming part of Letters Patent No. 534,581, dated February19, 1895.

Application filed May 23, 1894. Serial No. 512,202. (No model.)

To aZZ whom it may concern.-

Be it known that I, ADDISON V. SANFORD, of Elmira,in the county ofOhemung and State of New York, have invented a certain new and usefulImprovement in Artificial Ear- Drums; and I do hereby declare that thefollowing is a full, clear, and exact description of the same, referencebeing had to the drawings accompanying this application.

My invention relates to that class of devices which are made of thinrubber and introduced into the auditory canal, with a pad or filamentthat rests against the natural tympanum for the purpose of magnifyingthe sound waves and thereby assisting the hearing. Such devices are wellknown.

The invention consists of a device of peculiar construction ashereinafter more fully described and embodied in the claim.

In the drawingsFigure 1 is a side elevation of the device. Fig. 2 is alongitudinal section of the same. Fig. 3 is an elevation of the outerend.

This device, consisting of two end plates and a tubular connection, ismade entirely of rubber or some equivalent soft material.

a indicates the outer plate; I), the inner one, and c the connectingtube. The plates are of concave form.

The device is inserted in the auditory canal small end inward, and thesmall plate I) is made to fit and cover the natural tympanum, while theouter plate is located outside the passage and serves to receive thevibrations and convey them inward. Both plates are very thin, by whichmeans they are rendered sensitive to the vibrations of the air and thereis less tendency to produce irritation and soreness of the auditorycanal. Ordinarily the outer plate is about three fourths of an inch indiameter, the inner plate three eighths of an inch, and the tube oneinch long; but these sizes may be varied as necessity requires. Thebacks of the plates,

at their junction with the tube, are supplemented by small ribs 61,forming shoulders, Which serve to stiffen the plates at that pointwithout interfering with their flexibility and elasticity. body.

f is a diaphragm consisting of a very thin The device forms one integralmembrane of rubber or any suitable mate rial stretched across the mouthof the outer plate, which latter is provided with one or moreperforations g, which allows air to pass through and ventilate the ear.This diaphragm serves as a sensitive medium to convey the soundwaves tothe ear, and is much more effective than the plates alone. Both platesare made concave as shown, the outer one giving space for propervibrations of the diaphragm, and the inner one fitting the tympanum ofthe ear.

Artificial ear drums have before been made with plates at both ends, butusually of the same size. By making them of unequal sizes, as shown inmy drawings, the inner one is made to accurately cover the tympanum andthereby cover the nerve tissues, while the outer one covers the openingof the ear passage and concentrates the sound waves so that they arecarried to the organs of hearing in the most effective manner. Tubularstems have also before been known.

The device is inserted by a suitable probe which grasps the stem at theinner plate, and when once in place the soft tubular stem adapts itselfto the irregularities of the cavity and produces no irritation orinconvenience, while it serves to ventilate the ear and to convey thesound waves to the inner end. The thin diaphragm at the outer end, byreason of its sensitive vibrations to the waves of the outer air,greatly increases the efficiency of the device.

To apply the device in the ear the inner plate is folded down orcollapsed like an umbrella, and is then grasped by the pliers be yondthe end of the tube and held in that position while being inserted.\Vhen fully entered it is released, when it spreads out to cover thetympanum. Usually the pliers are withdrawn slightly to grasp the tube,which latter is then pushed forward to seat the plate. The device iseasily applied and removed.

Having described my invention I do not claim broadly a tube with a plateattached at one or both ends, but

What I claim as new, and desire to secure by Letters Patent, is

An artificial ear drum consisting of a flexible tube, plates at oppositeends integral therewith, one plate fitting thenatnral tympanum, my namein the presence of two subscribing the other resting outside theauditory passage witnesses. and having a perforation in its back, and avibratory diaphragm stretched across the outer 5 plate, as shown anddescribed and for the pur- W'itnesses:

pose specified. ROBT. XV. BUSH,

In Witness whereof I have hereunto signed H. L. HALLIDAY.

ADDISON V. SANFORD.

